(1) Field of the Invention
The present invention relates to apparatus which convert the movement of a fluid, particularly air or water, into rotational mechanical motion for the generation of mechanical power or other useful purposes. In this invention, naturally flowing air as wind or water as tidal, creek, stream or river flow impinges upon hinged blades mounted on a central disk. The force of fluid upon the hinged blades induces torque to a central disk which causes it to rotate thereby producing useful rotational mechanical motion. The rotational mechanical motion may be transmitted to a generator to produce electricity or to another power take-off device to extract useful work.
The present invention further relates to apparatus which are small and economical and which may be placed in a naturally occurring stream of water or in a location with sufficient winds to generate small quantities of electrical power or other useful work. The present invention still further relates to apparatus which may be large to enormous size and placed in naturally occurring windy areas on land, or in rivers, tidal estuaries, or other large moving bodies of water, to generate large quantities of electrical energy or other useful work.
(2) Background of the Invention
Engineers have long envisioned using the natural movement of water or air as a source of energy to operate electrical power generating stations or to produce useful power for other purposes. The most commonly envisioned system using water as the motive source includes a reservoir behind a dam from which water is caused to pass through a generating station from a higher to lower elevation above and below the dam. Useful energy is also extracted from the natural movement of air by the wind turbine for generating electrical power and the wind mill for producing useful work, such as pumping water or the grinding or milling of grains.
Although these systems are generally feasible for extracting useful work from the natural movement of air or water, they require large infrastructures like dams and power generation stations or large wind turbines. Electrical power generation from the movement of water in rivers requires a dam to artificially create a substantial vertical change in height of water to produce a sufficient head or water pressure. Power generation from tidal variations are generally considered economical and practical only at the extreme northern and southern latitudes, where there is substantial difference in the elevations between high and low tides.
In spite of the difficulties in extracting useful hydroelectric power, the costs for natural gas and coal have risen to a point where renewable sources of power generation are cost-competitive. In an effort to halt climate change and cut energy imports, almost half of the states in the United States have mandated that a share of their power come from alternative or green sources. This is causing demand for alternative energy sources to increase substantially. More than two dozen companies worldwide are developing systems to extract useful power from movement of waves and currents. One of the early commercial projects is a snake-like steel tube that floats, semi-submerged, in the ocean. This device and others like it are designed to extract large quantities of power from the movement of water.
The United States Department of Energy's (DOE) “Wind Powering America” initiative has set a goal of producing five percent of the nation's electricity from wind by 2020. DOE projects meant to achieve this goal will provide $60 billion in capital investment to rural America, $1.2 billion in new income to farmers and rural landowners, and 80,000 new jobs during the next 20 years. See Wind Powering America, Draft Action Plan, Jun. 18, 1999, U.S. Department of Energy, Wind Energy Program, page 2. Farming regions in the Midwest, Great Plains, and West have emerged as major growth areas for the production of power from wind. Wind power is growing partly as a result of technology improvements and cost reductions and partly in response to state and federal laws and incentives.
Large-scale power generation from the movement of air typically requires wind turbines with blades ranging in length from 70 to 100 feet or more. The supporting posts for these blades range from about 200 to 295 feet high. Small wind generators are also known, ranging from 400 watts to 40 kilowatts or more. Wind generators of this size can meet the needs of a small family or group of families or can be targeted to specific applications. For example, a family could use a wind-driven power generator to pump water for cattle or irrigation or to light their home.
In less developed countries, there is a lack of large-scale need sufficient to justify a great expenditure of money for commercial scale electrical power generating systems and the need for electrical or other useful power is measured more by that required by an individual or his family. In these instances, wind- or water-driven power generators are much cheaper than extending power lines and are more convenient, cheaper, and less polluting than gasoline or diesel generators.
Devices for generating useful power from the wind or from tidal flow which are characterized by erratic directions of flow require steering to point the power generating device into the wind or flowing water stream or tidal flow to maximize power generation. Further, changes in direction of the wind or water can cause the device to rotate in a different direction, i.e., from clockwise to counter-clockwise or vice versa. The steering device adds a complexity to power generating devices used in natural environments with erratic flow directions of the motive fluid which is overcome by the inventive features of the invention described herein. Any changes in direction of rotation of the power generating device can cause momentary loss of power generation as the device transitions from clockwise to counter-clockwise rotation.
This invention meets the need for a small and portable apparatus for generating electrical energy or other useful power from the natural movement of water or air across its surfaces and where the flow direction of the motive fluid is erratic or may even change as much as 180 degrees in a few moments. The invention rotates in the same clockwise or counter-clockwise direction regardless of the direction of flow of the motive fluid. The invention is scalable so that it may be adapted to large scale power generation commonly associated with the developed countries.
(3) Description of the Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
Although U.S. patents or published patent applications are known which disclose various power generation devices, none of them disclose a small, portable and scalable apparatus for the extraction of mechanical energy from the natural and unpredictable movement of air and water by the means disclosed herein.
The prior art includes several devices for converting the kinetic or potential energy of naturally occurring air or water into mechanical energy or that utilize hinged blades, but none anticipate nor in combination render obvious the invention described here. Examples of power generation or motive force from the action of water upon blades may be found in U.S. Pat. Nos. 4,039,847 and 5,697,822 and in U.S. Pat. Appl. No. 2007/0182159 A1. Patents and patent applications pertaining to power generation from the wind may be found in U.S. Pat. Nos. 4,186,314; 4,278,896; 5,518,362; 6,361,275 B1 and 6,779,966 B2.
Diggs, U.S. Pat. No. 4,039,847, discloses a device and method of converting tidal currents into power. The device is comprised of one or more modules positioned in tidal water. Each module has a turbine mounted on an elevator means which moves the turbine vertically in response to water level changes during a tide. Useful power is withdrawn from the turbine. The disclosed device requires vertical movement of the turbine so that water is caused to flow over it to maintain power generation. The device disclosed in this invention does not require such limitation.
Souter, U.S. Pat. No. 5,697,822, discloses a water walking apparatus comprising a pair of buoyant platforms with paddles mounted on each of their bottom surfaces. The paddles rotate rearwardly when the user moves the apparatus forward, thus reducing resistance to forward movement. The paddles rotate forward against a specially structured stop whenever there is any backward or slipping motion of the apparatus thus resisting any backward movement of the apparatus. This device only creates useful energy as forward motion in one direction of use. The hinged blades are affixed in a linear arrangement which limits its ability to produce the desired forward motion in bodies of water which are still or flowing in a direction opposing the desired direction of motion at a rate less than the speed of forward motion.
Davis, U.S. Pat. Appl. No. 2007/0182159 A1, discloses a power generating system designed to be placed within a manhole. The system generates electricity from water flowing through sewer lines by positioning a hydro turbine that can be raised and lowered into water flowing through sewer lines. The device has fixed blades and therefore does not meet the limitations of the invention disclosed herein.
Diggs, U.S. Pat. No. 4,186,314, discloses a wind power machine for the commercial conversion of wind power into electrical energy. The wind power machine employs flip-flop wind blades which travel in an oval path and are carried by traveling chains. The Diggs device requires a chain to carry the blades in a uniform up and down direction when the device is steered into the wind. Diggs discloses a steering mechanism to point the flip-flop wind blades into the wind. The invention disclosed herein does not require steering the device into the motive fluid.
McFarland, U.S. Pat. No. 4,278,896, discloses a wind power generator with a plurality of vertically spaced rotor assemblies rotatably mounted on the support assembly and connected to an electrical generator so that electrical energy is generated as the rotors are rotated by wind. The blades are fixed upon the rotor assembly and must be steered into the wind and therefore do not meet the limitation of hinged blades.
Kivilammi, U.S. Pat. No. 5,518,362, describes a device and method for transforming wind energy into electrical energy. The device comprises several fixed rotors rotating by wind energy and connected to electricity producing generators. The blades are fixed and therefore do not meet the limitation of hinged connection to the rotor.
Wobben, U.S. Pat. No. 6,361,275 B1, reveals a wind power installation with a rotor having at least one rotor blade for converting the kinetic energy of the wind into mechanical energy and an adjusting device to make adjustments to the rotor blade based upon instantaneous loading due to local, temporary peaks in the wind speed in the rotor area. The blades are moveable about the hub but are not hinged and the device must be pointed into the wind for maximum power generation. The Wobben device does not meet the limitations of the invention disclosed herein.
Smith, U.S. Pat. No. 6,779,966 B2, discloses device and method that captures wind energy and converts it into mechanical rotational energy. The system uses rotatable airfoils that capture wind energy to generate a mechanical force, an energy coupling means for transferring the mechanical force to a horizontally mountable wheel having a shaft coupled thereto, and an energy transfer system that couples the mechanical force from the shaft to a machine. The Smith device does not disclose hinged flat blades and does not rotate in the same direction if the motive fluid changes direction by 180 degrees and therefore does not meet the limitations of the invention disclosed herein.